Scientists have developed a simple DNA blood test which they claim can predict obesity levels in children as they grow up.

Researchers at the universities of Southampton, Exeter and Plymouth have found that the test, which is carried out when a child is five years old, can predict how much body fat they will have when they are 14. The test checks a gene called the PGC1 that regulates body fat storage.

Dr Graham Burdge, of the University of Southampton, said: "It can be difficult to predict when children are very young, which children will put on weight or become obese. It is important to know which children are at risk because help, such as suggestions about their diet, can be offered early and before they start to gain weight.

"The results of our study provide further evidence that being overweight or obese in childhood is not just due to lifestyle, but may also involve important basic processes that control our genes.

"We hope that this knowledge will help us to develop and test new ways to prevent children developing obesity which can be introduced before a child starts to gain excess weight. However, our findings now need to be tested in larger groups of children."